Plant hormones, and the control of growth
- Created by: amity.dauntless.erudite
- Created on: 04-05-15 11:33
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- control of plant growth
- Gravitropism
- growth in responses to the direction of light.
- Positive gravitropism
- The root tip grows towards gravity so there is more chance of finding moisture.
- Negative gravitropism
- In the stem tip to go away from the force of gravity , so there is more chance of finding light.
- Phototropism
- Growth in response to the direction of light.
- Positive Phototropism
- Is in the stem tip so the shoot grows towards the light, to get maximum light for photosynthesis
- Negative phototropism
- This is in the root tip to stop it from growing towards the light and drying out.
- "Tropism" is a growth in response to a stimulus.
- Plants grow towards, gravity, light and moisture.
- Positive tropism is where it grows towards the stimulus
- Negative tropism is away from the stimulus.
- Auxin
- It is a plant hormone produced by in the stem tips and roots, which controls the direction of growth.
- Auxin gathers on the lower side of the root and stem.
- In the root it grows more on the side with the least auxin making it bend and grow towards gravity.
- Once it has grown down the auxin becomes evenly spread again.
- In the shoot it grows more in the side with the most auxin, so it bends and grows up and away from the force of gravity.
- When it has grown up the auxin becomes evenly spread again.
- Auxin changes the elasticity of the cells
- The more elastic the cells are the more they grow and absorb more water.
- causing bending.
- The more elastic the cells are the more they grow and absorb more water.
- Gravitropism
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